Added pooling for path segments.

[PascalSenn]

Adds pool for path segments

|                      Method |         Mean |     Error |    StdDev |       Median | Rank |    Gen 0 | Gen 1 | Gen 2 | Allocated |
|---------------------------- |-------------:|----------:|----------:|-------------:|-----:|---------:|------:|------:|----------:|
|      V12_CreateNotManyPaths |     924.5 ns |   4.87 ns |   4.56 ns |     923.2 ns |    1 |   2.0847 |     - |     - |    4360 B |
|   Pooled_CreateNotManyPaths |   3,957.2 ns |  78.61 ns | 172.56 ns |   3,976.2 ns |    2 |        - |     - |     - |         - |
|    V12_CreateManyNamedPaths |  92,758.1 ns | 532.62 ns | 498.21 ns |  92,621.1 ns |    3 | 208.6182 |     - |     - |  436400 B |
| Pooled_CreateManyNamedPaths | 130,444.7 ns | 542.89 ns | 507.82 ns | 130,477.9 ns |    4 |        - |     - |     - |         - |